Kevint0609

i have a 2007 v6 4.0L mustang, and my vents blow no air. Now i have searched past threads and videos and no help for my situation. I work at an autoparts store so i have already bought, installed, and had no luck with : the blower motor itself, the resistor, the resistor connector, the fan control switch, and the fuses and relays. i still have no luck, no air blows through the vents. i have tried everything i can think of and tried everything i have found. i see no exposed or damaged wires, i can't imagine what to do next but take it to the shop which bugs the **** out of me because i already bought all these parts and installed them, just to have it end up in the shop. please help with any suggestions you have, i will try everything.

Siber Express

Have you changed the control switch itself, without it the fan switch doesn't get power.
That would be the switch all the way to the right

HRnB

You say that "air doesn't come out of the vents".
1. Does the fan even turn on?

a. If yes, then it's vent tubes pulled out and not getting to your vents.

b. If no, then the actual fan switch (you replaced) or relay (you replaced) or the actual control switch that switches to floor, dash defrost, is bad and stuck in the "neutral" position and not sending power to the fan.

You can try jumping the fan right off of the battery. But chances are it's a fan relay.
I know you said that you replaced the fan relay. So double check that you installed the relay correctly. They can be installed backwards. It's not a one way only relay. So check the numbers next to the relay pins that they are going into the sockets with matching numbers.

Second and most probable from your description, it's the relay block itself. The part that the relay pins plug into. There's a lot of heat generated on the fuse block and the heater fan relay especially, plus being under the hood, weather conditions can cause weak continuity and even arcing.

You can jump the relay if you follow the N/C N/O diagram on the relay.
But the easiest way to check bad continuity on the relay block is to start the car, turn fan switch on high, have a friend sit in the car while you jiggle the fan relay around to hear if the fan is turning on and off.
If so, replace or fix the relay/fuse block.

HRnB has spoken!

mhnamaki

Hi all,
I have the same problem. The fan doesn't work for both A/C and Heater. I can feel both A/C and Heater slightly in the cabin even at 4 setting.

The mechanic told me that the problem is for my "fan switch" and I have to change the "HVAC control assembly" totally which is very expensive (655$).

Do you have any idea how I can change the switch by myself? Does he mean that the problem is the fan ****? or anything behind the control assembly?

He told me that blower motor and wiring are fine.

Thanks.

007 v6

I would get one from a junk yard / "recycler" / salvage yard or look for a used one on eBay.